本研究內容中主要以聚偏氟乙烯-六氟丙烯共聚物(Poly (vinylidene fluoride)-hexafluoropropylene，PVDF-HFP)為高分子主體，並利用聚碳酸亞丙酯(Poly (propylene carbonate)，PPC)進行混摻，雙層式高分子層間再配合添加微量的離子液體，並加入參雜不同金屬之Li7La3Zr2O12 (LLZO)以及多壁奈米碳管(MWCNTs)形成複合型類固態電解質，探討高分子中加入奈米填料對於材料以及電化學性質的影響。本研究中製備的複合型固態電解質，除了能有效抑制系統結晶程度，進而提供鋰離子有更多之運動空間，也能結合PVDF-HFP與PPC高分子的優點來提升其電化學表現。由實驗結果得知高分子主體PVDF-HFP摻入適量的PPC交聯後，並搭配應用在NMC-811正極系統時，於室溫25 °C下有優異的電化學表現：低速比放電容量(191.40 mAh/g @ 25 mA/g)、高速比放電容量(100.56 mAh/g @ 300 mA/g)、高離子導通率(5.74×10-4 S/cm)；接續下來之研究實驗得到高分子固態電解質中添加不同含量之多壁奈米碳管(MWCNTs)，對於整體固態電解質電性表現上確實也有明顯提升，由結果可得知當1 wt.% MWCNTs添加有最佳電性表現：低速比電容量(198.18 mAh/g @ 25 mA/g)高速比電容量(110.90 mAh/g @ 300 mA/g)、高離子導通率(7.39×10-4 S/cm)。另一部分之研究實驗得到高分子固態電解質中添加不同參雜條件之LLZO粉末，對於整體固態電解質電性表現上確實有明顯提升，藉由此複合性固態電解質討論於一次燒結條件下(900 ℃，10小時)之不同過量添加碳酸鋰添加量之LLZO參雜Ga(LLZGO)的差異，可發現當10 wt.% 過量鋰添加有最佳電性表現：低速比電容量(209.62 mAh/g @ 25 mA/g)、高速比電容量(119.81 mAh/g @ 300 mA/g)、高離子導通率(7.02×10-4 S/cm)；最後一部分之研究實驗一樣藉由此複合性固態電解質中加入LLZO共參雜0.25Ga與不同參雜量的Ce，可發現LLZO共參雜0.25Ga與不同參雜量的Ce當有最佳電性表現：低速比電容量 (208.10 mAh/g @ 25 mA/g)、高速比電容量(144.15 mAh/g @ 300 mA/g)、高離子導通率(1.38×10-3 S/cm)。本研究中不同填充物添加之固態電解質於電性上有明顯提升，進階證實了PVDF-HFP混摻PPC之改質並添加適量LLZO以及MWCNTs有助於固態電解質於未來之應用。;In this research, PVDF-HFP was used as the main polymer, and PPC was mixed to tune the properties of the solid electrolyte. MWCNT, Li6.25La3Zr2Ga0.25O12 (LLZGO) or Li6.25La3Zr1.7Ga0.25Ce0.2O12 (LLZGCO) were added as the inorganic filler to form a composite solid-state electrolyte. We want to study effects of nanofillers on electrochemical properties.The composite solid electrolyte prepared in this study can not only effectively suppress the crystallinity of the system, thereby providing more movement space for lithium ions, but also take advantage of the two polymers to improve the chemical potential window and the lithium ion conductivity. In the first part of experiment, it was found that adding different contents of multi-walled carbon nanotubes (MWCNTs) into the polymer solid electrolyte significantly improve the electrical performance of the overall solid electrolyte. It can be seen from the results that the best electrochemical performance is obtained when 1wt.% MWCNT is added:specific capacity of 198.18 mAh/g @ 25mA/g, and ionic conductivity of 7.39×10-4 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte. In the second part of experiment, LLZGO powder were added as the inorganic filler. It was found that LLZGO powder with the different doping condition has improved the electrical performance of the overall solid electrolyte. It can be found that when 10wt.% excess lithium was added, ,the cell shows the best electrochemical performance : specific capacity of 209.62 mAh/g @ 25mA/g & 119.81 mAh/g @ 300 mA/g ,and ionic conductivity of 7.02×10-4 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte. In the final part of the research, LLZGCO powder were added as the inorganic filler. It was found that LLZO powder with the different doping condition has improved the electrical performance of the overall solid electrolyte. It can be found that when 10wt.% excess lithium is added ,it has the best electrochemical performance : specific capacity of 208.10 mAh/g @ 25mA/g & 144.15 mAh/g @ 300 mA/g ,and ionic conductivity of 1.38×10-3 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte. In this study, the electrical properties of the solid electrolytes are significantly improved due to inorganic fillers. It is further confirmed that the modification of PVDF-HFP mixed with PPC and the addition of appropriate amounts of MWCNT, LLZGCO and LLZO were helpful for the future application of solid electrolytes.
